1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Glue Code for assembler optimized version of 3DES
4 *
5 * Copyright �� 2014 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
6 *
7 * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
8 *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
9 */
10
11#include <crypto/algapi.h>
12#include <crypto/des.h>
13#include <crypto/internal/skcipher.h>
14#include <linux/crypto.h>
15#include <linux/init.h>
16#include <linux/module.h>
17#include <linux/types.h>
18
19struct des3_ede_x86_ctx {
20	struct des3_ede_ctx enc;
21	struct des3_ede_ctx dec;
22};
23
24/* regular block cipher functions */
25asmlinkage void des3_ede_x86_64_crypt_blk(const u32 *expkey, u8 *dst,
26					  const u8 *src);
27
28/* 3-way parallel cipher functions */
29asmlinkage void des3_ede_x86_64_crypt_blk_3way(const u32 *expkey, u8 *dst,
30					       const u8 *src);
31
32static inline void des3_ede_enc_blk(struct des3_ede_x86_ctx *ctx, u8 *dst,
33				    const u8 *src)
34{
35	u32 *enc_ctx = ctx->enc.expkey;
36
37	des3_ede_x86_64_crypt_blk(enc_ctx, dst, src);
38}
39
40static inline void des3_ede_dec_blk(struct des3_ede_x86_ctx *ctx, u8 *dst,
41				    const u8 *src)
42{
43	u32 *dec_ctx = ctx->dec.expkey;
44
45	des3_ede_x86_64_crypt_blk(dec_ctx, dst, src);
46}
47
48static inline void des3_ede_dec_blk_3way(struct des3_ede_x86_ctx *ctx, u8 *dst,
49					 const u8 *src)
50{
51	u32 *dec_ctx = ctx->dec.expkey;
52
53	des3_ede_x86_64_crypt_blk_3way(dec_ctx, dst, src);
54}
55
56static void des3_ede_x86_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
57{
58	des3_ede_enc_blk(crypto_tfm_ctx(tfm), dst, src);
59}
60
61static void des3_ede_x86_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
62{
63	des3_ede_dec_blk(crypto_tfm_ctx(tfm), dst, src);
64}
65
66static int ecb_crypt(struct skcipher_request *req, const u32 *expkey)
67{
68	const unsigned int bsize = DES3_EDE_BLOCK_SIZE;
69	struct skcipher_walk walk;
70	unsigned int nbytes;
71	int err;
72
73	err = skcipher_walk_virt(&walk, req, false);
74
75	while ((nbytes = walk.nbytes)) {
76		u8 *wsrc = walk.src.virt.addr;
77		u8 *wdst = walk.dst.virt.addr;
78
79		/* Process four block batch */
80		if (nbytes >= bsize * 3) {
81			do {
82				des3_ede_x86_64_crypt_blk_3way(expkey, wdst,
83							       wsrc);
84
85				wsrc += bsize * 3;
86				wdst += bsize * 3;
87				nbytes -= bsize * 3;
88			} while (nbytes >= bsize * 3);
89
90			if (nbytes < bsize)
91				goto done;
92		}
93
94		/* Handle leftovers */
95		do {
96			des3_ede_x86_64_crypt_blk(expkey, wdst, wsrc);
97
98			wsrc += bsize;
99			wdst += bsize;
100			nbytes -= bsize;
101		} while (nbytes >= bsize);
102
103done:
104		err = skcipher_walk_done(&walk, nbytes);
105	}
106
107	return err;
108}
109
110static int ecb_encrypt(struct skcipher_request *req)
111{
112	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
113	struct des3_ede_x86_ctx *ctx = crypto_skcipher_ctx(tfm);
114
115	return ecb_crypt(req, ctx->enc.expkey);
116}
117
118static int ecb_decrypt(struct skcipher_request *req)
119{
120	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
121	struct des3_ede_x86_ctx *ctx = crypto_skcipher_ctx(tfm);
122
123	return ecb_crypt(req, ctx->dec.expkey);
124}
125
126static unsigned int __cbc_encrypt(struct des3_ede_x86_ctx *ctx,
127				  struct skcipher_walk *walk)
128{
129	unsigned int bsize = DES3_EDE_BLOCK_SIZE;
130	unsigned int nbytes = walk->nbytes;
131	u64 *src = (u64 *)walk->src.virt.addr;
132	u64 *dst = (u64 *)walk->dst.virt.addr;
133	u64 *iv = (u64 *)walk->iv;
134
135	do {
136		*dst = *src ^ *iv;
137		des3_ede_enc_blk(ctx, (u8 *)dst, (u8 *)dst);
138		iv = dst;
139
140		src += 1;
141		dst += 1;
142		nbytes -= bsize;
143	} while (nbytes >= bsize);
144
145	*(u64 *)walk->iv = *iv;
146	return nbytes;
147}
148
149static int cbc_encrypt(struct skcipher_request *req)
150{
151	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
152	struct des3_ede_x86_ctx *ctx = crypto_skcipher_ctx(tfm);
153	struct skcipher_walk walk;
154	unsigned int nbytes;
155	int err;
156
157	err = skcipher_walk_virt(&walk, req, false);
158
159	while (walk.nbytes) {
160		nbytes = __cbc_encrypt(ctx, &walk);
161		err = skcipher_walk_done(&walk, nbytes);
162	}
163
164	return err;
165}
166
167static unsigned int __cbc_decrypt(struct des3_ede_x86_ctx *ctx,
168				  struct skcipher_walk *walk)
169{
170	unsigned int bsize = DES3_EDE_BLOCK_SIZE;
171	unsigned int nbytes = walk->nbytes;
172	u64 *src = (u64 *)walk->src.virt.addr;
173	u64 *dst = (u64 *)walk->dst.virt.addr;
174	u64 ivs[3 - 1];
175	u64 last_iv;
176
177	/* Start of the last block. */
178	src += nbytes / bsize - 1;
179	dst += nbytes / bsize - 1;
180
181	last_iv = *src;
182
183	/* Process four block batch */
184	if (nbytes >= bsize * 3) {
185		do {
186			nbytes -= bsize * 3 - bsize;
187			src -= 3 - 1;
188			dst -= 3 - 1;
189
190			ivs[0] = src[0];
191			ivs[1] = src[1];
192
193			des3_ede_dec_blk_3way(ctx, (u8 *)dst, (u8 *)src);
194
195			dst[1] ^= ivs[0];
196			dst[2] ^= ivs[1];
197
198			nbytes -= bsize;
199			if (nbytes < bsize)
200				goto done;
201
202			*dst ^= *(src - 1);
203			src -= 1;
204			dst -= 1;
205		} while (nbytes >= bsize * 3);
206	}
207
208	/* Handle leftovers */
209	for (;;) {
210		des3_ede_dec_blk(ctx, (u8 *)dst, (u8 *)src);
211
212		nbytes -= bsize;
213		if (nbytes < bsize)
214			break;
215
216		*dst ^= *(src - 1);
217		src -= 1;
218		dst -= 1;
219	}
220
221done:
222	*dst ^= *(u64 *)walk->iv;
223	*(u64 *)walk->iv = last_iv;
224
225	return nbytes;
226}
227
228static int cbc_decrypt(struct skcipher_request *req)
229{
230	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
231	struct des3_ede_x86_ctx *ctx = crypto_skcipher_ctx(tfm);
232	struct skcipher_walk walk;
233	unsigned int nbytes;
234	int err;
235
236	err = skcipher_walk_virt(&walk, req, false);
237
238	while (walk.nbytes) {
239		nbytes = __cbc_decrypt(ctx, &walk);
240		err = skcipher_walk_done(&walk, nbytes);
241	}
242
243	return err;
244}
245
246static int des3_ede_x86_setkey(struct crypto_tfm *tfm, const u8 *key,
247			       unsigned int keylen)
248{
249	struct des3_ede_x86_ctx *ctx = crypto_tfm_ctx(tfm);
250	u32 i, j, tmp;
251	int err;
252
253	err = des3_ede_expand_key(&ctx->enc, key, keylen);
254	if (err == -ENOKEY) {
255		if (crypto_tfm_get_flags(tfm) & CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)
256			err = -EINVAL;
257		else
258			err = 0;
259	}
260
261	if (err) {
262		memset(ctx, 0, sizeof(*ctx));
263		return err;
264	}
265
266	/* Fix encryption context for this implementation and form decryption
267	 * context. */
268	j = DES3_EDE_EXPKEY_WORDS - 2;
269	for (i = 0; i < DES3_EDE_EXPKEY_WORDS; i += 2, j -= 2) {
270		tmp = ror32(ctx->enc.expkey[i + 1], 4);
271		ctx->enc.expkey[i + 1] = tmp;
272
273		ctx->dec.expkey[j + 0] = ctx->enc.expkey[i + 0];
274		ctx->dec.expkey[j + 1] = tmp;
275	}
276
277	return 0;
278}
279
280static int des3_ede_x86_setkey_skcipher(struct crypto_skcipher *tfm,
281					const u8 *key,
282					unsigned int keylen)
283{
284	return des3_ede_x86_setkey(&tfm->base, key, keylen);
285}
286
287static struct crypto_alg des3_ede_cipher = {
288	.cra_name		= "des3_ede",
289	.cra_driver_name	= "des3_ede-asm",
290	.cra_priority		= 200,
291	.cra_flags		= CRYPTO_ALG_TYPE_CIPHER,
292	.cra_blocksize		= DES3_EDE_BLOCK_SIZE,
293	.cra_ctxsize		= sizeof(struct des3_ede_x86_ctx),
294	.cra_alignmask		= 0,
295	.cra_module		= THIS_MODULE,
296	.cra_u = {
297		.cipher = {
298			.cia_min_keysize	= DES3_EDE_KEY_SIZE,
299			.cia_max_keysize	= DES3_EDE_KEY_SIZE,
300			.cia_setkey		= des3_ede_x86_setkey,
301			.cia_encrypt		= des3_ede_x86_encrypt,
302			.cia_decrypt		= des3_ede_x86_decrypt,
303		}
304	}
305};
306
307static struct skcipher_alg des3_ede_skciphers[] = {
308	{
309		.base.cra_name		= "ecb(des3_ede)",
310		.base.cra_driver_name	= "ecb-des3_ede-asm",
311		.base.cra_priority	= 300,
312		.base.cra_blocksize	= DES3_EDE_BLOCK_SIZE,
313		.base.cra_ctxsize	= sizeof(struct des3_ede_x86_ctx),
314		.base.cra_module	= THIS_MODULE,
315		.min_keysize		= DES3_EDE_KEY_SIZE,
316		.max_keysize		= DES3_EDE_KEY_SIZE,
317		.setkey			= des3_ede_x86_setkey_skcipher,
318		.encrypt		= ecb_encrypt,
319		.decrypt		= ecb_decrypt,
320	}, {
321		.base.cra_name		= "cbc(des3_ede)",
322		.base.cra_driver_name	= "cbc-des3_ede-asm",
323		.base.cra_priority	= 300,
324		.base.cra_blocksize	= DES3_EDE_BLOCK_SIZE,
325		.base.cra_ctxsize	= sizeof(struct des3_ede_x86_ctx),
326		.base.cra_module	= THIS_MODULE,
327		.min_keysize		= DES3_EDE_KEY_SIZE,
328		.max_keysize		= DES3_EDE_KEY_SIZE,
329		.ivsize			= DES3_EDE_BLOCK_SIZE,
330		.setkey			= des3_ede_x86_setkey_skcipher,
331		.encrypt		= cbc_encrypt,
332		.decrypt		= cbc_decrypt,
333	}
334};
335
336static bool is_blacklisted_cpu(void)
337{
338	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
339		return false;
340
341	if (boot_cpu_data.x86 == 0x0f) {
342		/*
343		 * On Pentium 4, des3_ede-x86_64 is slower than generic C
344		 * implementation because use of 64bit rotates (which are really
345		 * slow on P4). Therefore blacklist P4s.
346		 */
347		return true;
348	}
349
350	return false;
351}
352
353static int force;
354module_param(force, int, 0);
355MODULE_PARM_DESC(force, "Force module load, ignore CPU blacklist");
356
357static int __init des3_ede_x86_init(void)
358{
359	int err;
360
361	if (!force && is_blacklisted_cpu()) {
362		pr_info("des3_ede-x86_64: performance on this CPU would be suboptimal: disabling des3_ede-x86_64.\n");
363		return -ENODEV;
364	}
365
366	err = crypto_register_alg(&des3_ede_cipher);
367	if (err)
368		return err;
369
370	err = crypto_register_skciphers(des3_ede_skciphers,
371					ARRAY_SIZE(des3_ede_skciphers));
372	if (err)
373		crypto_unregister_alg(&des3_ede_cipher);
374
375	return err;
376}
377
378static void __exit des3_ede_x86_fini(void)
379{
380	crypto_unregister_alg(&des3_ede_cipher);
381	crypto_unregister_skciphers(des3_ede_skciphers,
382				    ARRAY_SIZE(des3_ede_skciphers));
383}
384
385module_init(des3_ede_x86_init);
386module_exit(des3_ede_x86_fini);
387
388MODULE_LICENSE("GPL");
389MODULE_DESCRIPTION("Triple DES EDE Cipher Algorithm, asm optimized");
390MODULE_ALIAS_CRYPTO("des3_ede");
391MODULE_ALIAS_CRYPTO("des3_ede-asm");
392MODULE_AUTHOR("Jussi Kivilinna <jussi.kivilinna@iki.fi>");
393